1 /* 2 * workqueue.h --- work queue handling for Linux. 3 */ 4 5 #ifndef _LINUX_WORKQUEUE_H 6 #define _LINUX_WORKQUEUE_H 7 8 #include <linux/timer.h> 9 #include <linux/linkage.h> 10 #include <linux/bitops.h> 11 #include <asm/atomic.h> 12 13 struct workqueue_struct; 14 15 struct work_struct; 16 typedef void (*work_func_t)(struct work_struct *work); 17 18 /* 19 * The first word is the work queue pointer and the flags rolled into 20 * one 21 */ 22 #define work_data_bits(work) ((unsigned long *)(&(work)->data)) 23 24 struct work_struct { 25 atomic_long_t data; 26 #define WORK_STRUCT_PENDING 0 /* T if work item pending execution */ 27 #define WORK_STRUCT_NOAUTOREL 1 /* F if work item automatically released on exec */ 28 #define WORK_STRUCT_FLAG_MASK (3UL) 29 #define WORK_STRUCT_WQ_DATA_MASK (~WORK_STRUCT_FLAG_MASK) 30 struct list_head entry; 31 work_func_t func; 32 }; 33 34 #define WORK_DATA_INIT(autorelease) \ 35 ATOMIC_LONG_INIT((autorelease) << WORK_STRUCT_NOAUTOREL) 36 37 struct delayed_work { 38 struct work_struct work; 39 struct timer_list timer; 40 }; 41 42 struct execute_work { 43 struct work_struct work; 44 }; 45 46 #define __WORK_INITIALIZER(n, f) { \ 47 .data = WORK_DATA_INIT(0), \ 48 .entry = { &(n).entry, &(n).entry }, \ 49 .func = (f), \ 50 } 51 52 #define __WORK_INITIALIZER_NAR(n, f) { \ 53 .data = WORK_DATA_INIT(1), \ 54 .entry = { &(n).entry, &(n).entry }, \ 55 .func = (f), \ 56 } 57 58 #define __DELAYED_WORK_INITIALIZER(n, f) { \ 59 .work = __WORK_INITIALIZER((n).work, (f)), \ 60 .timer = TIMER_INITIALIZER(NULL, 0, 0), \ 61 } 62 63 #define __DELAYED_WORK_INITIALIZER_NAR(n, f) { \ 64 .work = __WORK_INITIALIZER_NAR((n).work, (f)), \ 65 .timer = TIMER_INITIALIZER(NULL, 0, 0), \ 66 } 67 68 #define DECLARE_WORK(n, f) \ 69 struct work_struct n = __WORK_INITIALIZER(n, f) 70 71 #define DECLARE_WORK_NAR(n, f) \ 72 struct work_struct n = __WORK_INITIALIZER_NAR(n, f) 73 74 #define DECLARE_DELAYED_WORK(n, f) \ 75 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f) 76 77 #define DECLARE_DELAYED_WORK_NAR(n, f) \ 78 struct dwork_struct n = __DELAYED_WORK_INITIALIZER_NAR(n, f) 79 80 /* 81 * initialize a work item's function pointer 82 */ 83 #define PREPARE_WORK(_work, _func) \ 84 do { \ 85 (_work)->func = (_func); \ 86 } while (0) 87 88 #define PREPARE_DELAYED_WORK(_work, _func) \ 89 PREPARE_WORK(&(_work)->work, (_func)) 90 91 /* 92 * initialize all of a work item in one go 93 * 94 * NOTE! No point in using "atomic_long_set()": useing a direct 95 * assignment of the work data initializer allows the compiler 96 * to generate better code. 97 */ 98 #define INIT_WORK(_work, _func) \ 99 do { \ 100 (_work)->data = (atomic_long_t) WORK_DATA_INIT(0); \ 101 INIT_LIST_HEAD(&(_work)->entry); \ 102 PREPARE_WORK((_work), (_func)); \ 103 } while (0) 104 105 #define INIT_WORK_NAR(_work, _func) \ 106 do { \ 107 (_work)->data = (atomic_long_t) WORK_DATA_INIT(1); \ 108 INIT_LIST_HEAD(&(_work)->entry); \ 109 PREPARE_WORK((_work), (_func)); \ 110 } while (0) 111 112 #define INIT_DELAYED_WORK(_work, _func) \ 113 do { \ 114 INIT_WORK(&(_work)->work, (_func)); \ 115 init_timer(&(_work)->timer); \ 116 } while (0) 117 118 #define INIT_DELAYED_WORK_NAR(_work, _func) \ 119 do { \ 120 INIT_WORK_NAR(&(_work)->work, (_func)); \ 121 init_timer(&(_work)->timer); \ 122 } while (0) 123 124 /** 125 * work_pending - Find out whether a work item is currently pending 126 * @work: The work item in question 127 */ 128 #define work_pending(work) \ 129 test_bit(WORK_STRUCT_PENDING, work_data_bits(work)) 130 131 /** 132 * delayed_work_pending - Find out whether a delayable work item is currently 133 * pending 134 * @work: The work item in question 135 */ 136 #define delayed_work_pending(w) \ 137 work_pending(&(w)->work) 138 139 /** 140 * work_release - Release a work item under execution 141 * @work: The work item to release 142 * 143 * This is used to release a work item that has been initialised with automatic 144 * release mode disabled (WORK_STRUCT_NOAUTOREL is set). This gives the work 145 * function the opportunity to grab auxiliary data from the container of the 146 * work_struct before clearing the pending bit as the work_struct may be 147 * subject to deallocation the moment the pending bit is cleared. 148 * 149 * In such a case, this should be called in the work function after it has 150 * fetched any data it may require from the containter of the work_struct. 151 * After this function has been called, the work_struct may be scheduled for 152 * further execution or it may be deallocated unless other precautions are 153 * taken. 154 * 155 * This should also be used to release a delayed work item. 156 */ 157 #define work_release(work) \ 158 clear_bit(WORK_STRUCT_PENDING, work_data_bits(work)) 159 160 161 extern struct workqueue_struct *__create_workqueue(const char *name, 162 int singlethread, 163 int freezeable); 164 #define create_workqueue(name) __create_workqueue((name), 0, 0) 165 #define create_freezeable_workqueue(name) __create_workqueue((name), 0, 1) 166 #define create_singlethread_workqueue(name) __create_workqueue((name), 1, 0) 167 168 extern void destroy_workqueue(struct workqueue_struct *wq); 169 170 extern int FASTCALL(queue_work(struct workqueue_struct *wq, struct work_struct *work)); 171 extern int FASTCALL(queue_delayed_work(struct workqueue_struct *wq, struct delayed_work *work, unsigned long delay)); 172 extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, 173 struct delayed_work *work, unsigned long delay); 174 extern void FASTCALL(flush_workqueue(struct workqueue_struct *wq)); 175 176 extern int FASTCALL(schedule_work(struct work_struct *work)); 177 extern int FASTCALL(run_scheduled_work(struct work_struct *work)); 178 extern int FASTCALL(schedule_delayed_work(struct delayed_work *work, unsigned long delay)); 179 180 extern int schedule_delayed_work_on(int cpu, struct delayed_work *work, unsigned long delay); 181 extern int schedule_on_each_cpu(work_func_t func); 182 extern void flush_scheduled_work(void); 183 extern int current_is_keventd(void); 184 extern int keventd_up(void); 185 186 extern void init_workqueues(void); 187 void cancel_rearming_delayed_work(struct delayed_work *work); 188 void cancel_rearming_delayed_workqueue(struct workqueue_struct *, 189 struct delayed_work *); 190 int execute_in_process_context(work_func_t fn, struct execute_work *); 191 192 /* 193 * Kill off a pending schedule_delayed_work(). Note that the work callback 194 * function may still be running on return from cancel_delayed_work(). Run 195 * flush_scheduled_work() to wait on it. 196 */ 197 static inline int cancel_delayed_work(struct delayed_work *work) 198 { 199 int ret; 200 201 ret = del_timer_sync(&work->timer); 202 if (ret) 203 work_release(&work->work); 204 return ret; 205 } 206 207 #endif 208